Meteorology

Meteorology is a science that studies the processes and phenomena of the atmosphere.

Meteorology is subdivided into many specialty areas including—but not limited to—physical meteorology (dealing with physical aspects of the atmosphere such as rain or cloud formation, or rainbows and mirages), synoptic meteorology (the analysis and forecast of large-scale weather systems), dynamic meteorology (studies of change based upon the laws of theoretical physics and geochemistry), climatology, aviation meteorology, atmospheric chemistry, atmospheric optics, and agricultural meteorology. While meteorology usually refers to the study of Earth's atmosphere, atmospheric science can include the study of the atmospheres of all the planets in the solar system.

Greek philosopher and scientist Aristotle (384–322 B.C.), the first to use the word meteorology in his book Meteorologica (c. 340 B.C.,) summarizing the knowledge of that time about atmospheric phenomena. He speculatively wrote about clouds, rain, snow, wind, and climatic changes, and although many of his findings later proved to be incorrect, many of them were insightful.

Although systematic weather data recording began about the fourteenth century, the lack of weather measuring instruments made only visual observations possible at that time. The real scientific study of atmospheric phenomena started later with the invention of devices to measure weather data: the thermometer in about 1600 for measuring temperature, the barometer for measuring atmospheric pressure in 1643, the anemometer for measuring wind speed in 1667, and the hair hygrometer for measuring humidity in 1780. In 1802, the first cloud classification system was formulated, and in 1805, a wind scale was first introduced. These measuring instruments and new ideas made possible gathering of actual data from the atmosphere giving the basis for scientific theories for properties of the atmosphere (pressure, temperature, humidity, etc.) and its governing physical laws.

In the early 1840s, the first weather forecasting services started with the use of the telegraph to transmit meteorological information. At that time, meteorology was still in the descriptive phase, and relied on simple observation with little scientific theories and calculations involved, although weather maps could be drawn, and storm systems and surface wind patterns were being recognized.

Meteorology became more scientifically rigorous during World War I, when Norwegian physicist Vilhelm Bjerknes (1862–1951) introduced a modern meteorological theory stating that weather patterns in the temperate middle latitudes are the result of the interaction between warm and cold air masses. His descriptions of atmospheric phenomena and forecasting techniques were based on the laws of physics, and stipulated that predictions could be made of atmospheric dynamics based on physical laws.

Advances in understand physical events also translate to advances in understanding dynamics on a global scale. For example, a nucleation event is the process of condensation or aggregation (gathering) that results in the formation of larger drops or crystals around a material that acts as a structural nucleus around which such condensation or aggregation proceeds. Moreover, the introduction of such structural nuclei can often induce the processes of condensation or crystal growth. Accordingly, nucleation is one of the ways that a phase transition can take place in a material. These fundamentals regarding nucleation are true whether in a microchemistry experiment or in the formation of rain and snow crystals.

In addition to an importance in explaining a wide variety of geophysical and geochemical phenomena—including crystal formation—the principles of nucleation were used in cloud seeding weather modification experiments where nuclei of inert materials were dispersed into clouds with the hopes of inducing condensation and rainfall.

By the 1940s, upper-level measurements of pressure, temperature, wind and humidity clarified more about the vertical properties of the atmosphere. In the 1950s, radar became important for detecting precipitation over a remote area. Also in the 1950s, with the invention of the computer, weather forecasting became not only quicker but also more reliable, because the computers could solve the mathematical equations of the atmospheric models much faster. In 1960, the first meteorological satellite was launched to provide 24-hour monitoring of weather events worldwide.

These satellites now give three-dimensional data to high-speed computers for faster and more precise weather predictions. Computers are capable of plotting the observation data, and solving huge models not only for near-term weather forecasting, but also climatic models on time scales of centuries. Predictions still contain degrees of uncertainty, computers still have their capacity limits and the models used still contain many uncertainties. Advances in prediction reliability are critical because changes in climate and weather—especially predicitios involving severe weather events such as hurricanes and tornadoes—can greatly and adversely impact both personal safety and economic interests.

Many complicated issues remain at the forefront of meteorology, including air pollution, global warming, El Niño events, climate change, ozone hole, and acid rain issues.